diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..3e923cfb8 100644
--- a/exercises/B-hello-world/exercise.js
+++ b/exercises/B-hello-world/exercise.js
@@ -1 +1,15 @@
 console.log("Hello world");
+
+//* Try to `console.log()` something different. For example, 'Hello World. I just started learning JavaScript!'.
+console.log('Hello World. I just started learning JavaScript!');
+
+// * Try to console.log() several things at once.
+let greeting = "Hello";
+let firstName = "Kara";
+console.log(`${greeting} ${firstName}`);
+
+//* What happens when you get rid of the quote marks?
+//console.log(Hello, World!);    SyntaxError: missing ) after argument list
+
+//* What happens when you console.log() just a number without quotes?
+console.log(12345);
diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..da6348264 100644
--- a/exercises/C-variables/exercise.js
+++ b/exercises/C-variables/exercise.js
@@ -1,3 +1,6 @@
 // Start by creating a variable `greeting`
-
-console.log(greeting);
+var greeting = "Hello world";
+//* Print your `greeting` to the console 3 times
+for (i = 0; i < 3; i++){
+    console.log(greeting);
+}
\ No newline at end of file
diff --git a/exercises/D-strings/exercise.js b/exercises/D-strings/exercise.js
index 2cffa6a81..aa5c65ca9 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `message`
-
+//* Write a program that logs a message and its type
+let message = "This is a string";
 console.log(message);
+console.log(typeof message);
diff --git a/exercises/E-strings-concatenation/exercise.js b/exercises/E-strings-concatenation/exercise.js
index 2cffa6a81..999734039 100644
--- a/exercises/E-strings-concatenation/exercise.js
+++ b/exercises/E-strings-concatenation/exercise.js
@@ -1,3 +1,6 @@
 // Start by creating a variable `message`
-
+//* Write a program that logs a message with a greeting and your name
+let greetingStart = "Hello, my name is ";
+let myName = "Kara";
+let message = greetingStart + myName;
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..c26eca748 100644
--- a/exercises/F-strings-methods/exercise.js
+++ b/exercises/F-strings-methods/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `message`
-
+//* Log a message that includes the length of your name
+let myName = "Kara";
+let message = `My name is ${myName} and my name is ${myName.length} characters long`;
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..9f9afa155 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,6 @@
-const name = " Daniel  ";
+//* Log the same message using the variable, `name` provided
+//* Use the `.trim` method to remove the extra whitespace
 
-console.log(message);
+const name = " Daniel  ";
+let message = `My name is ${name.trim()} and my name is ${name.length} characters long`;
+console.log(message);
\ No newline at end of file
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..c0ac27e99 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,7 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+//* Create two variables `numberOfStudents` and `numberOfMentors`
+//* Log a message that displays the total number of students and mentors
+let numberOfStudents = 15;
+let numberOfMentors = 8;
+let total = numberOfStudents + numberOfMentors
+console.log(`Number of Students: ${numberOfStudents}\nNumber of Mentors: ${numberOfMentors}\nTotal number of students and mentors: ${total}`);
\ No newline at end of file
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..284da2c4e 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,9 @@
 var numberOfStudents = 15;
 var numberOfMentors = 8;
+
+//* Using the variables provided in the exercise calculate the percentage of mentors and students in the group
+let total = numberOfStudents + numberOfMentors;
+let percentageStudents = Math.round((numberOfStudents / total) * 100);
+let percentageMentors = Math.round((numberOfMentors / total) * 100);
+console.log(`Percentage students: ${percentageStudents}%`);
+console.log(`Percentage mentors: ${percentageMentors}%`);
\ No newline at end of file
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..c8b0373db 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,7 +1,13 @@
+//* Complete the function in exercise.js so that it halves the input
+//* Try calling the function more than once with some different numbers
+
 function halve(number) {
-  // complete the function here
+  return number / 2;
 }
 
 var result = halve(12);
-
 console.log(result);
+result = halve(14);
+console.log(result);
+result = halve(16);
+console.log(result);
\ No newline at end of file
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..6deefdc5d 100644
--- a/exercises/J-functions/exercise2.js
+++ b/exercises/J-functions/exercise2.js
@@ -1,5 +1,7 @@
+//* Complete the function in exercise2.js so that it triples the input
+
 function triple(number) {
-  // complete function here
+  return number * 3;
 }
 
 var result = triple(12);
diff --git a/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..768d0b9c0 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,6 +1,8 @@
+//* Write a function that multiplies two numbers together
 // Complete the function so that it takes input parameters
-function multiply() {
+function multiply(num1, num2) {
   // Calculate the result of the function and return it
+  return num1 * num2;
 }
 
 // Assign the result of calling the function the variable `result`
diff --git a/exercises/K-functions-parameters/exercise2.js b/exercises/K-functions-parameters/exercise2.js
index db7a8904b..4eafe7a0a 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,5 +1,8 @@
+//* From scratch, write a function that divides two numbers
 // Declare your function first
-
+function divide(num1, num2){
+    return num1 / num2;
+}
 var result = divide(3, 4);
 
 console.log(result);
diff --git a/exercises/K-functions-parameters/exercise3.js b/exercises/K-functions-parameters/exercise3.js
index 537e9f4ec..dec5ecbf7 100644
--- a/exercises/K-functions-parameters/exercise3.js
+++ b/exercises/K-functions-parameters/exercise3.js
@@ -1,5 +1,8 @@
+//* Write a function that takes a name (a string) and returns a greeting
 // Write your function here
-
+function createGreeting(name){
+    return `Hello, my name is ${name}`;
+}
 var greeting = createGreeting("Daniel");
 
 console.log(greeting);
diff --git a/exercises/K-functions-parameters/exercise4.js b/exercises/K-functions-parameters/exercise4.js
index 7ab44589e..3b2a4473e 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,9 @@
+//* Write a function that adds two numbers together
+//* Call the function, passing `13` and `124` as parameters, and assigning the returned value to a variable `sum`
 // Declare your function first
-
+function addNumbers(num1, num2){
+    return num1 + num2;
+}
 // Call the function and assign to a variable `sum`
-
-console.log(sum);
+let sum = addNumbers(13, 124);
+console.log(sum);
\ No newline at end of file
diff --git a/exercises/K-functions-parameters/exercise5.js b/exercises/K-functions-parameters/exercise5.js
index 7c5bcd605..52046558c 100644
--- a/exercises/K-functions-parameters/exercise5.js
+++ b/exercises/K-functions-parameters/exercise5.js
@@ -1,4 +1,8 @@
+//* Write a function that takes a name (a string) and an age (a number) and returns a greeting (a string)
 // Declare your function here
+function createLongGreeting(name, age){
+    return `Hello, my name is ${name} and I am ${age} years old`;
+}
 
 const greeting = createLongGreeting("Daniel", 30);
 
diff --git a/exercises/L-functions-nested/exercise.js b/exercises/L-functions-nested/exercise.js
index a5d377442..0693d91a7 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -1,5 +1,12 @@
-var mentor1 = "Daniel";
-var mentor2 = "Irina";
-var mentor3 = "Mimi";
-var mentor4 = "Rob";
-var mentor5 = "Yohannes";
+//- In `exercise.js` write a program that displays the percentage of students and mentors in the group
+//- The percentage should be rounded to the nearest whole number (use a search engine to find out how to this with JavaScript)
+//- You should have one function that calculates the percentage, and one function that creates a message
+
+function percentageOfStudentsAndMentors(numberOfStudents, numberOfMentors){
+    let total = numberOfStudents + numberOfMentors;
+    let percentageStudents = Math.round((numberOfStudents / total) * 100);
+    let percentageMentors = Math.round((numberOfMentors / total) * 100);
+    return `Percentage mentors: ${percentageStudents}%\nPercentage students: ${percentageMentors}%`;
+}
+
+console.log(percentageOfStudentsAndMentors(15, 8));
\ No newline at end of file
diff --git a/exercises/L-functions-nested/exercise2.js b/exercises/L-functions-nested/exercise2.js
new file mode 100644
index 000000000..029fd87ea
--- /dev/null
+++ b/exercises/L-functions-nested/exercise2.js
@@ -0,0 +1,13 @@
+//- In `exercise2.js` you have been provided with the names of some mentors. Write a program that logs a shouty greeting to each one.
+//- Your program should include a function that spells their name in uppercase, and a function that creates a shouty greeting.
+//- Log each greeting to the console.
+
+function shoutyGreeting(mentorName){
+    return `hello ${mentorName}`.toUpperCase();
+}
+
+let mentors = ["Daniel", "Irina", "Mimi", "Rob", "Yohannes"];
+
+for (i = 0; i < 5; i++){
+    console.log(shoutyGreeting(mentors[i]));
+}
diff --git a/extra/1-currency-conversion.js b/extra/1-currency-conversion.js
index 70a2fe863..d7a93dca3 100644
--- a/extra/1-currency-conversion.js
+++ b/extra/1-currency-conversion.js
@@ -5,8 +5,10 @@
   Write a function that converts a price to USD (exchange rate is 1.4 $ to £)
 */
 
-function convertToUSD() {}
-
+function convertToUSD(priceInPounds) {
+  return priceInPounds * 1.4;
+}
+console.log(convertToUSD(32));
 /*
   CURRENCY FORMATTING
   ===================
@@ -15,7 +17,10 @@ function convertToUSD() {}
   They have also decided that they should add a 1% fee to all foreign transactions, which means you only convert 99% of the £ to BRL.
 */
 
-function convertToBRL() {}
+function convertToBRL(priceInPounds) {
+  return (priceInPounds * 0.99) * 5.7;
+}
+console.log(convertToBRL(30));
 
 /* ======= TESTS - DO NOT MODIFY ===== 
 There are some Tests in this file that will help you work out if your code is working.
diff --git a/extra/2-piping.js b/extra/2-piping.js
index 067dd0f5b..d14121f44 100644
--- a/extra/2-piping.js
+++ b/extra/2-piping.js
@@ -16,26 +16,31 @@
   the final result to the variable goodCode
 */
 
-function add() {
-
+function add(num1, num2) {
+    return num1 + num2;
 }
+console.log(add(1, 3));
 
-function multiply() {
-
+function multiply(num1, num2) {
+    return num1 * num2;
 }
+console.log(multiply(2, 3));
 
-function format() {
-
+function format(number) {
+    return `£${number}`;
 }
+console.log(format(16));
 
-const startingValue = 2
+const startingValue = 2;
 
 // Why can this code be seen as bad practice? Comment your answer.
-let badCode = 
+let badCode = add(startingValue, 10); badCode = multiply(badCode, 2); console.log(badCode = format(badCode)); // code all on one line is difficult to read
 
 /* BETTER PRACTICE */
-
-let goodCode = 
+// Comments can be added to explain each line and it is easier to read
+let goodCode = add(startingValue, 10); // function call to add 10 to startingValue and store result in goodCode
+goodCode = multiply(goodCode, 2); // function call to multiply value of goodCode by 2
+console.log(goodCode = format(goodCode)); // function call to format value of goodCode
 
 /* ======= TESTS - DO NOT MODIFY ===== 
 There are some Tests in this file that will help you work out if your code is working.
diff --git a/extra/3-magic-8-ball.js b/extra/3-magic-8-ball.js
index e32182cfe..e046b7756 100644
--- a/extra/3-magic-8-ball.js
+++ b/extra/3-magic-8-ball.js
@@ -45,10 +45,53 @@
 
 // This should log "The ball has shaken!"
 // and return the answer.
+
+// Object "possibleAnswers" declared for the 4 categories to set up key:value pairs
+let possibleAnswers = {
+  veryPositive: ["It is certain.", "It is decidedly so.", "Without a doubt.", "Yes - definitely.", "You may rely on it."],
+  positive: ["As I see it, yes.", "Most likely.", "Outlook good.", "Yes.", "Signs point to yes."],
+  negative: ["Reply hazy, try again.", "Ask again later.", "Better not tell you now.", "Cannot predict now.", "Concentrate and ask again."],
+  veryNegative: ["Don't count on it.", "My reply is no.", "My sources say no.", "Outlook not so good.", "Very doubtful."]
+}
+
+// Random number function
+function getRandomNumber(min, max) {
+  // Produces a random decimal number between 0-1 then multiplies it by the range then adds the min value. Rounds to nearest number.
+  return Math.round(Math.random() * (max - min) + min);
+}
+
+// Variable used in shakeBall() function and checkAnswer function to select an answer from the array of the chosen category (passes in a random number between 0 and 4)
+let answerSelection = getRandomNumber(0 , 4);
+
 function shakeBall() {
-  //Write your code in here
+  console.log("The ball has shaken!");
+  let randomNumber = getRandomNumber(1, 4);
+  let answer = "";
+
+  if (randomNumber == 1) {
+    // if the random number selected is 1, then variable "answer" is assigned the value of a random selection (0-4) from the "veryPositive" values array in the possibleAnswers object
+    answer = possibleAnswers.veryPositive[answerSelection];
+    return(answer);
+  }
+  else if (randomNumber == 2) {
+    // if the random number selected is 2, then variable "answer" is assigned the value of a random selection (0-4) from the "positive" values array in the possibleAnswers object
+    answer = possibleAnswers.positive[answerSelection];
+    return(answer);
+  }
+  else if (randomNumber == 3) {
+    // if the random number selected is 3, then variable "answer" is assigned the value of a random selection (0-4) from the "negative" values array in the possibleAnswers object
+    answer = possibleAnswers.negative[answerSelection];
+    return(answer);
+  }
+  else if (randomNumber == 4) {
+    // if the random number selected is 4, then variable "answer" is assigned the value of a random selection (0-4) from the "veryNegative" values array in the possibleAnswers object
+    answer = possibleAnswers.veryNegative[answerSelection];
+    return(answer);
+  }
 }
 
+console.log(shakeBall()); 
+
 /* 
   This function should say whether the answer it is given is
     - very positive
@@ -58,10 +101,29 @@ function shakeBall() {
 
   This function should expect to be called with any value which was returned by the shakeBall function.
 */
-function checkAnswer(answer) {
+
+function checkAnswer(answer, answerSelection) {
   //Write your code in here
+   // if the "veryPositive" values in the possibleAnswers object include the string assigned to "answer" at the index specified by "answerSelection", then return "very positive"
+  if (possibleAnswers.veryPositive.includes(answer, [answerSelection])) {
+    return "very positive";
+  }
+  // if the "positive" values in the possibleAnswers object include the string assigned to "answer" at the index specified by "answerSelection", then return "positive"
+  else if (possibleAnswers.positive.includes(answer, [answerSelection])) {
+    return "positive";
+  }
+  // if the "negative" values in the possibleAnswers object include the string assigned to "answer" at the index specified by "answerSelection", then return "negative"
+  else if (possibleAnswers.negative.includes(answer, [answerSelection])) {
+    return "negative";
+  }
+  // if the "veryNegative" values in the possibleAnswers object include the string assigned to "answer" at the index specified by "answerSelection", then return "very negative"
+  else if (possibleAnswers.veryNegative.includes(answer, [answerSelection])) {
+    return "very negative";
+  }
 }
 
+checkAnswer();
+console.log();
 /* 
 ==================================
 ======= TESTS - DO NOT MODIFY =====
diff --git a/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index 0a21afd1b..6f498d235 100644
--- a/mandatory/1-syntax-errors.js
+++ b/mandatory/1-syntax-errors.js
@@ -1,16 +1,17 @@
 // There are syntax errors in this code - can you fix it to pass the tests?
 
-function addNumbers(a b c) {
+function addNumbers(a, b, c) {
     return a + b + c;
 }
 
-function introduceMe(name, age)
-return "Hello, my name is " + name "and I am " age + "years old";
+function introduceMe(name, age) {
+    return "Hello, my name is " + name + " and I am " + age + " years old";
+}
 
 function getTotal(a, b) {
-    total = a ++ b;
+    total = a + b;
 
-    return "The total is total"
+    return "The total is " + total;
 }
 
 /* 
diff --git a/mandatory/2-logic-error.js b/mandatory/2-logic-error.js
index 3c578ad87..1f1245b39 100644
--- a/mandatory/2-logic-error.js
+++ b/mandatory/2-logic-error.js
@@ -1,16 +1,15 @@
 // The syntax for this function is valid but it has an error, find it and fix it.
 
 function trimWord(word) {
-  return wordtrim();
+  return word.trim();
 }
 
 function getWordLength(word) {
-  return "word".length();
+  return word.length;
 }
 
 function multiply(a, b, c) {
-  a * b * c;
-  return;
+  return a * b * c;
 }
 
 /* 
diff --git a/mandatory/3-function-output.js b/mandatory/3-function-output.js
index c9221a200..dca103231 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -1,18 +1,21 @@
 // Add comments to explain what this function does. You're meant to use Google!
 function getNumber() {
-  return Math.random() * 10;
+  return Math.random() * 10; // returns the number entered multiplied by a random integer from 0 to 9
 }
 
 // Add comments to explain what this function does. You're meant to use Google!
 function s(w1, w2) {
-  return w1.concat(w2);
+  return w1.concat(w2); // concatenates w1 and w2 without white space
 }
 
 function concatenate(firstWord, secondWord, thirdWord) {
   // Write the body of this function to concatenate three words together.
+  return `${firstWord} ${secondWord} ${thirdWord}`;
   // Look at the test case below to understand what this function is expected to return.
 }
 
+console.log(concatenate("Code","Your","Future"));
+
 /* 
 ===================================================
 ======= TESTS - DO NOT MODIFY BELOW THIS LINE =====
diff --git a/mandatory/4-tax.js b/mandatory/4-tax.js
index c9e41c691..6186aaaf7 100644
--- a/mandatory/4-tax.js
+++ b/mandatory/4-tax.js
@@ -5,7 +5,10 @@
   Sales tax is 20% of the price of the product
 */
 
-function calculateSalesTax() {}
+function calculateSalesTax(productPrice) {
+  return productPrice * 1.2;
+}
+console.log(calculateSalesTax(15));
 
 /*
   CURRENCY FORMATTING
@@ -17,8 +20,11 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function addTaxAndFormatCurrency() {}
-
+function addTaxAndFormatCurrency(productPrice) {
+  let totalCost = productPrice * 1.2;
+  return `£${totalCost.toFixed(2)}`; // fixes to 2 decimal places
+}
+console.log(addTaxAndFormatCurrency(15));
 /* 
 ===================================================
 ======= TESTS - DO NOT MODIFY BELOW THIS LINE =====